Structural, magnetic and magnetocaloric properties of La0.8Ba0.2Mn1−xFexO3 compounds with 0 ⩽ x ⩽ 0.1

The present study reports the effect of Fe doping on the structural, magnetic and magnetocaloric proprieties in the La0.8Ba0.2Mn1−xFexO3 (0 ⩽ x ⩽ 0.1) perovskites. The studied samples were synthesized as powder samples by solid state reaction at high temperature. Their analysis by powder X-ray diffraction using Rietveld refinement showed that they crystallize in the rhombohedral system with the R3¯C space group. They display a paramagnetic (PM)-ferromagnetic (FM) phase transition with decreasing temperature. All of them exhibit a maximum and large magnetocaloric effect near the Curie temperature (TC  ). The magnitude of the isothermal magnetic entropy |ΔSMmax| at the FM Curie temperature decreases from 4.15 J kg−1 K−1 for the x = 0 composition to 2.62 J kg−1 K−1 for x = 0.1, for a magnetic field change of 5T. For an applied magnetic field of 5T, the relative cooling power (RCP) values are found to vary between 211 and 238 J kg−1. The phenomenon of large entropy change and the convenient adjustment of the Curie temperature make these peroskite-type manganese oxides useful for magnetic refrigeration in an extended high temperature range even at room temperature.

► The prepared samples exhibit paramagnetic–ferromagnetic phase transition (TC). ► La0.8Ba0.2MnO3 exhibits the highest value of 4.15 J/(K kg) for TC = 295 K. ► The field dependence of ΔSM change is also analyzed showing the power law dependence. ► Critical behavior of the transition for manganites is sensitive to the Mn-site.